Liquid-supply system



Nov. 3, 1925' 1,560,044 w. 1. DERRICK LIQUID SUPPLY SYSTEM Filed July 5,1922 Patented Nov. 3, 1925.

UNITED STATES PATENT OFFICE.

WILLIAM I. DERRICK,.OF MO'LINE, ILLINOIS, ASSIGNOR TO WESTGO-CHIPPEWAPUMP COMPANY, OF DAVENPORT, IOWA, A CORPORATION OF DELAWARE.

LIQUID-SUPPLY SYSTEM.

Application fileg July 3,

To all whom. it may concern:

Be it known that I, WILLIAM I. DERRICK, a citizen of the United States,residing at Moline, in the county of Rock Island and 5 State ofIllinois, have invented certaln new and useful Improvements in Liqud-Supply Systems, of which the following 1s a spoolfication, referencebeing bad to the accompanying drawings. I

This invention relates to pumping systems and more particularly toliquid supply systems such as systems for furnishing water forresidences, hotels, apartments, commericial purposes, etc.

An object of this invention is to provide an automatic pumping systemcapable of delivering an ample supply of water at a desired pressuredirectly through service pipes.

' Another object of the invention 18 to provide a system which will pumpwhen water is desired and in suflicient quantities so that large andinconvenient storage tanks heretofore used in such pressure systems areeliminated and yet all the advantages of such systems are retained.

Another object of the invention 15 to provide a system in which apressure compensator is located between the pump discharge 30 and themotor controlling means in order to prevent sudden or momentaryfluctuations in the pressure from affecting the pressure operated motorcontrolling mechanlsm.

Another object of the invention is to provide a small tank oraccumulator which causes the replacement of small losses of water fromthe discharge line, thus preventing a quick drop in the pressure in theline. due to leakage such as might be caused by incompletely closedfaucets, faulty valves. etc.

Another object of the invention is to provide such a tank or accumulatorwhich cannot become water logged or full of water in service to insure asufiieient quantity of compressible gas at all times to expand when thepressure is reduced and replace small losses of water from the system.

The following description and annexed drawings set forth in detailcertain means embodying my invention, the disclosed 1922. Serial No.572,541.

means, however, constituting but one of the various mechanical forms inwhich the principle of the invention can be employed.

In said annexed drawings,

Figure 1 is a diagrammatic view of the system.

Fig. 2 is an enlarged longitudinal section of the tank or theaccumulator.

Fig. 3 is a section on line 33, Fig. 2.

In the drawings. 1 indicates a motor mounted on a suitable base 2 whichdrives a motor shaft 3. The shaft 4 of the pump 5 is connected by asuitable coupling 6 and is driven thereby. By way of example the pumpdiagrammatically illustrated consists of a casing in which is mountedarotor of the type in which a portion of the rotor engages the Water inan outer fluid channel. While this is the preferred type of pump it isto be understood that any pump capable of delivering a sufficient supplyof water at an appropriate pressure can be used.

' The pump 5 has an intake pipe 7 extending to a suitable source ofsupply 8. Leading from the pump is a discharge or service line 10 whichmay be extended to faucets 11 located in various places where it isdesired to deliver water. A suitable check valve 1.2 may be supplied atthe end of the intake pipe inthe source of water, to prevent the pumplosing its prime when the pump is not operating.

Between the discharge side of the pump and the automatic pressureoperated motor controlling switch 15 is a relatively small accumulatortank which is connected to the discharge side of the pump by line 21.The tank 20 consists of upper and lower sections 20 and 20 respectively,secured together by any suitable fastening means such as screws 23passing through the outturned flanges 24 of the upper section of thetank and threaded into the outturned flanges 25 of the lower section ofthe tank. A suitable diaphragm or membrane 26 preferably of a flexibleor yielding material such as rubber or the like, is clamped between theoutturned flanges and separates the upper and lower portions of thetank. By tightening the screws 23 or otherwise clamping the sections ofthe tank together the upper portion of the tank is rendered air-tightand the lower portion of the tank is rendered watertight.

. Communicating with the lower portion of the tank is a pipe 30 leadingto the pressure chamber 31 of the motor controlling switch 32.

The specific electric switch mechanism 1s not shown herein in detail,for any pressure actuated switch which is positive and efficient in itsoperation and perm ts var ation of pressure between its operating huntsand may be adjusted to vary or change such limits is suflicient. In sofar as the present invention is concerned, however, it is only necessarythat a diaphragm be provided which is subjected to the pressuretransmitted thru the tank 20 and is operable to open the motor switchwhen the pressure reaches a predetermined maximum and to close theswitch when the pressure drops to a predetermined minimum.

Suitable wiring connects the electric service line with the switch andmotor, so that when the switch is closed the motor will operate to drivethe pump.

When the pressure in the system falls below the predetermined amount forwhich the automatic pressure governor is set, the governor will operatethe switch l5 to close the motor circuit and the pump w1ll operate untilthe pressure is built up to a predetermined maximum, when the swltchw1ll be opened automatically by the pressure governor. As there is nostorage tank 1n the system, when a faucet is turned on the water comesdirectly from a well, the only old water being that which stood in thesupply and suction lines themselves, and that is quickly withdrawn.

The small tank or accumulator 20 operates as a permanent gas containerto assist in compensating pressure changes caused by opening or closinga faucet suddenly or starting the pump as the tank is located betweenthe pump and the motor controlling switch. Consequently, onlysubstantial or sus ained variations of pressure are transmitted throughthe tank to the switch.

Theaccumulator also acts to replace small losses ofwater from thedischarge line and to prevent a quick drop in the pressure in the linedue to leakage such as might be caused by failure to close the faucettightly, faulty valves, etc. It is possible for a small tank toaccomplish this result since it contains a gas, preferably air, which iscompressible, whereas water'or other liquid in the system is relativelyincompressible so that a considerable volume of water can leak from thesystem before the pressure in the tank is reduced sufliciently to permitthe motor switch 15 to be closed. If the pressure is reduced by leakagesufliciently to start the motor the pump 7 will again establish themaximum ressure in the tank 20 which will permit leakage for aconsiderable time before the motor is again operated. Without the tank aleak in the system would cause fluctuations of pressure in the linewhich would ca use the motor switch to be constant- 1y moving to andfrom closed position start-- in and stopping the motor which wouldsubject the pump motor and driving connections to excessive wear.

By having the air chamber 2 of the tank p sitively and permanentlysituated from the chamber 20 which may become filled with water duringuse, it will be seen that it is always possible to obtain the benefit ofa compressible medium such as air in the system, as it is not possiblefor the entire tank to become filled with water, or water logged, asheretofore.

Furthermore, it is to be understood that the particular forms ofapparatus shown and described, and the particular procedure set forth,are presented for purposes of explanation and illustration and thatvarious modifications of said apparatus and procedure can be madewithout departing from my invention as defined in the appended claims.

Having thus described my invention, what I claim is:

1. liquid supply system comprising in comhmation a pump, a suctionconduit extending from said pump to the source of supply. a dischargeconduit leading from the pump. means for driving said pump, a

pressure operating device for controlling said drlving means, anaccumulator interposed between said discharge conduit and said pressureoperating device, said accumulator comprising a plurality of chambers,one of said chambers containing a gas and being separated from the otherchamber by a fluid tight medium, said medium being adapted to transmitpressure from one chamher to the other.

2. liquid supply system comprising in combination a pump, a motor fordriving the same, discharge and inlet ports leading from and into thepump, a pressure operated motor controlling device, and an accumulatortank connected to the discharge side of the pump and to saidpressure-operated motor controlling device, said accumulator tank havingcompartments, one of said compartments being a gas'tight compartmentcapable of receiving pressure from and transmitting pressure to theother compartment.

3. A liquid supply systemcomprising in combination a pump, suction anddischarge lines connected to the pump, a motor for actuating the pump,an automatic motor controlling device, and a relatively smallaccumulator connected to the discharge line to replace fluid lossthrough leakage in the line, said accumulator having a gas chambersealed to prevent egress of gas and ingress of liquid.

4. A liquid supply system comprising in combination a pump, a suctionconduit extending from said pump to the source of supply, a dischargeconduit leading from the pump, means for driving said pump, a pressureoperating device for controlling said'driving means, andan accumulatorinterposed between said discharge conduit and said pressure operatingdevice, said accumulator comprising a plurality of chambers, one of saidchambers containing a gas and being separated from the other chamber bya fluid tight medium, said medium being adapted to transmit pressurefrom one chamber to the other, and means connecting saiil device withone of said chambers.

5. A liquid supply system comprising in combination a pump, means toactuate the same, a pressure operated device to control said actuatingmeans, an accumulator tank interposed between the pump and said pressureoperated device, said accumulator tank having superposed compartments,means connecting the discharge side of the pump and the pressureoperated device with the lower compartment, and means preventinginterchange of fluid between the compartments.

In testimony whereof I hereunto aflix my signature.

WILLIAM I. DERRIGK=

